Sensor-responsive control method and apparatus

• US 5,857,160 A
• Filed: 05/23/1996
• Issued: 01/05/1999
• Est. Priority Date: 05/23/1996
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Brown, Todd, Hu, Hong Xing, Pastor, Stephen Robert, Lee, Alan James, Salman, Mutasim Abdurrahman, Tierney, Gordon Leo, Carson, Douglass L., Dickinson, John E., Leaphart, Eldon Gerrald
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/664,321
• Time in Patent Office: 957 Days
• Field of Search: 364/424.051, 364/424.052, 364/424.053, 364/426.016, 364/426.01, 364/424.047, 364/424.029, 364/426.027, 364/424.045 , 364/424.054, 180/408, 180/410, 180/422, 180/446, 180/415, 180/421, 180/168, 180/282, 180/423, 180/233, 180/197, 280/707, 280/91.1, 701/41, 701/42, 701/36, 701/70
• US Class Current: 701/41
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2400/0513 Yaw angle
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/0533 Yaw acceleration
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/412 of steering wheel or column
• CPC Class Codes: B60G 2400/4122 Neutral position detection
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/1877 Adaptive Control
• CPC Class Codes: B60G 2600/60 Signal noise suppression; Electronic filtering means
• CPC Class Codes: B60G 2800/22 Braking, stopping
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• CPC Class Codes: B60T 2250/06 Sensor zero-point adjustment; Offset compensation

Abstract

A sensor-responsive control method for use on a motor vehicle, comprising the steps of: measuring a vehicle yaw rate; measuring a vehicle lateral acceleration; responsive to the measured yaw rate and lateral acceleration, estimating a steering wheel angle; determining an error signal responsive to the difference between the estimated steering wheel angle and an adaptive steering position signal; and updating the adaptive steering position signal responsive to the error signal, wherein the adaptive steering position signal is quickly determined after the vehicle begins to move.

Claims

1. A sensor responsive control method for use on a motor vehicle, comprising the steps of:

maintaining a position sensor-responsive steering position signal responsive to a vehicle steering position sensor, wherein the sensor-responsive steering position signal increases in response to angular rotation of a vehicle steering wheel in a first direction and decreases in response to angular rotation of the vehicle steering wheel in a second direction opposite the first direction;

measuring a vehicle yaw rate (102);

measuring a vehicle lateral acceleration (48);

responsive to the measured yaw rate and lateral acceleration estimating an estimated steering position signal (220);

determining an error signal responsive to the position sensor-responsive steering position signal and the estimated steering position signal (226); and

adaptively updating the position sensor-responsive steering of the position signal responsive to the error signal (114), wherein center position errors of the position sensor-responsive steering position signal are corrected for, wherein the step of measuring the vehicle yaw rate comprises the sub-steps of;

determining whether the vehicle is stopped (130);

receiving an output of a yaw rate sensor (48);

determining a yaw bias responsive to the output (140); and

determining the measured yaw rate as a sum of the yaw bias and the output (148).

2. A sensor-responsive control method for use on a motor vehicle, comprising the steps of:

maintaining a position sensor-responsive steering position signal responsive to a vehicle steering position sensor, wherein the sensor-responsive steering position signal increases in response to angular rotation of a vehicle steering wheel in a first direction and decreases in response to angular rotation of the vehicle steering wheel in a second direction opposite the first directions;

measuring a vehicle yaw rate (102);

measuring a vehicle lateral acceleration (48);

responsive to the measured yaw rate and lateral acceleration, estimating an estimated steering position signal (220);

determining an error signal responsive to the position sensor-responsive steering position signal and the estimated steering position signal (226); and

adaptively updating the position sensor-responsive steering position signal responsive to the error signal (114), wherein center position errors of the position sensor-responsive steering position signal are corrected for, wherein the step of measuring the vehicle yaw rate comprises the sub-steps of;

determining an initial estimate responsive to measured left and right wheel speeds of undriven left and right vehicle wheels (142,

     160); and

validating the initial estimate if the vehicle is not decelerating more than a first predetermined threshold, is not in an active brake control mode and is moving greater than a predetermined minimum speed (162), wherein the validated initial estimate is the measured yaw rate.

3. A sensor-responsive control method according to claim 2, wherein the step of measuring the vehicle yaw rate also comprises the sub-steps of:

determining a difference between the initial estimate and a present value estimated yaw rate (180);

updating a yaw rate bias responsive to the difference (196); and

determining the measured vehicle yaw rate responsive to the updated yaw rate bias (148).

4. A sensor-responsive control method for use on a motor vehicle, comprising the steps of:

maintaining a position sensor-responsive steering position signal responsive to a vehicle steering position sensor, wherein the sensor-responsive steering position signal increases in response to angular rotation of a vehicle steering wheel in a first direction and decreases in response to angular rotation of the vehicle steering wheel in a second direction opposite the first direction;

measuring a vehicle yaw rate (102);

measuring a vehicle lateral acceleration (48);

responsive to the measured yaw rate and lateral acceleration estimating an estimated steering position signal (220);

determining an error signal responsive to the position sensor-responsive steering position signal and the estimated steering position signal (2260; and

adaptively adjusting the position sensor-responsive steering position signal responsive to the error signal (114), wherein center position errors of the position sensor-responsive steering position signal are corrected for,

also comprising the step of initializing the position sensor-responsive steering position signal according to the sub-step of;

estimating an initial steering position signal responsive to the measured yaw rate and the measured lateral acceleration (220);

determining a difference between the initial steering position signal and the adjusted position sensor-responsive steering position signal (224); and

updating the adjusted position sensor-responsive steering position signal responsive to the difference (114).

5. A sensor-responsive control apparatus for use in a motor vehicle, comprising:

a steering sensor (40) providing position sensor signals responsive to movement of a steering wheel;

a position control maintaining a position sensor-responsive steer position signal (402) responsive to the position sensor signals, wherein the position sensor-responsive steer position signal is increased in response to angular rotation of the steering wheel in a first direction and is decreased in response to angular rotation of the steering wheel in a second direction opposite the first direction; and

an adaptive controller (362) for estimating an output indicative of steering position responsive to a signal indicative of measured vehicle yaw rate and for adaptively updating the position sensor-responsive steer position signal responsive to the estimated output, wherein position errors of the position sensor-responsive steer position signal are corrected for, wherein

(a) the position sensor signals comprise up signals when the steering wheel is turned in the first direction and down signals when the steering wheel is turned in the second direction, and

(b) the position control comprises a counter that increments in response to the up signals and decrements in response to the down signals.

6. A sensor-responsive control method for use in a motor vehicle, comprising the steps of:

maintaining a position sensor-responsive steering position signal responsive to a vehicle steering position sensor, wherein the sensor-responsive steering position signal increases in response to angular rotation of a vehicle steering wheel in a first direction and decreases in response to angular rotation of the vehicle steering wheel in a second direction opposite the first direction;

determining an estimated steering position responsive to vehicle yaw rate, and

adaptively adjusting the position sensor-responsive steering position signal responsive to the estimated steering position, wherein position errors of the position sensor-responsive steering position signal are corrected for;

wherein the step of maintaining the position sensor-responsive steering position signal comprises the substeps of;

receiving, from the vehicle steering position sensor, up signals when the steering wheel is rotated in the first direction and down signals when the steering wheel is rotated in the second direction;

incrementing the position sensor-responsive steering position signal in response to the up signals; and

decrementing the position sensor-responsive steering position signal in response to the down signals.